Welcome to Electric Lemon and its 101 uses for a lemon.

48) Make
a battery from a lemon

Name: Jenny Town: LondonCountry: UKsuggestion: All
you need for this experiment is
a lemon, a penny, and strip of zinc. Make sure the zinc and the penny
areclean
by polishing them with a piece of
sand paper. Squeeze the lemon without
splitting the peel to release the
juices inside. Cut
a pair of slits in the top of the
lemon about 1-2 cm apart. Insert
the penny in one slit and the zinc
in the other. Touching
the leads of a voltmeter to the
penny and the zinc will show that
a small voltage is produced.

WARNING:
A small number of people die each
year from testing batteries with
their tongue so don't do it, but
breaking open a battery with a pair
of pliers is fine!!